We should define our own classes of conformant implementation types, to avoid using the generic "presentation processor" or "transformation processor" ones. We could link to them.
At the moment, I can think of the following classes:

• DAPT Authoring Tool: tool that produces compliant DAPT documents or consumes DAPT compliant document. I don't think they map to TTML2 processors.
• DAPT Audio Recorder/Renderer: tool that takes DAPT Audio Description scripts, e.g. with mixing instruction, and produces audio output, e.g. a WAVE file. I think it is a "presentation processor"
• DAPT Validator: tool that verify that a DAPT document is compliant to the specification. I'm not sure what it maps to in TTML2 terminology.